Make slits in the eggplants and stuff some garlic in, and rub them with oil. Then roast the eggplants directly on the flame. Let the eggplants cool, then peel them.
Saute finely chopped onions and garlic until golden. Add garam masala, tumeric, cumin and tomatoes. Saute for a few minutes, then add eggplants and mash them. If the dish isn't smoky enough season with liquid smoke.
The eggplants can also be prepared in a 200 °C oven: Line a baking tray with aluminum foil. Bake for 1 hour, then put under a broiler for 10 minutes, turning every few minutes.